A known automatic analyzer designed to analyze amount of components contained in a sample irradiates a reaction solution, in which a sample and a reagent are mixed with each other, with light from a light source. The analyzer then measures the intensity of the obtained transmitted or scattered light with respect to a single wavelength or a plurality of wavelengths so as to determine the amount of a component on the basis of a relation between light intensity and concentration.
The automatic analyzer disclosed in patent document 1 includes a reaction disk that repeats rotation and stop, the reaction disk having optically transparent reaction cells arranged circumferentially thereon. While the reaction disk is rotating, a transmitted light measuring section disposed at a predetermined position in the automatic analyzer measures, for a period of approximately ten minutes, changes in the light intensity over time as a result of a reaction at predetermined time intervals (reaction process data). After the reaction, the reaction vessel is cleaned by a cleaning mechanism before being re-used for other analyses.
Two broad types of analysis fields exist for reactions of the reaction solution: specifically, a colorimetric analysis that uses a color reaction of a substrate and an enzyme; and a homogeneous immunoassay that uses an agglutination reaction by bonding of an antigen and an antibody. The immunoturbidimetric method and the latex coagulating method are known for the latter homogeneous immunoassay.
The immunoturbidimetric method uses a reagent containing an antibody to produce an immune complex with a substance to be measured (an antigen) contained in the sample. The immune complex is then optically detected to thereby determine component amount. The latex coagulating method uses a reagent that contains latex particles having an antibody sensitized (bonded) to their surfaces. The latex particles are agglutinated through an antigen-antibody reaction with the antigen contained in the sample. The agglutinated latex particles are then optically detected to thereby determine component amount. Analyzers performing even higher sensitive heterogeneous immunoassay are also known. These analyzers employ detection techniques by use of chemoluminescence and electrochemical luminescence and the B/F separation technique.
Patent document 2 discloses another automatic analyzer that measures coagulability of blood. Blood has fluidity inside the blood vessel; however, bleeding activates coagulation factors in the blood plasma and platelet in a chained manner, so that fibrinogen in the blood plasma turns to form fibrin, causing the bleeding to stop.
Blood coagulability may be exogenous where blood that escapes from the blood vessel coagulates, or endogenous where blood inside the blood vessel coagulates. Measurement items relating to the blood coagulability include prothrombin time (PT) as an exogenous blood coagulation reaction test and activated partial thromboplastin time (APTT) and a fibrinogen amount (Fbg) as an endogenous blood coagulation reaction test.
For each of these measurement items, a reagent that makes coagulation start is added to thereby cause deposition of fibrin and the resultant fibrin is detected with an optical, physical, or electrical technique. A known method employing the optical technique irradiates a reaction solution with light and identifies fibrin that deposits in the reaction solution as changes in intensity of scattered light or transmitted light over time, thereby calculating the time at which the fibrin starts deposition. In blood coagulation automatic analyzers represented by the automatic analyzer disclosed in patent document 2, blood coagulation reactions (Fbg item, in particular) feature a short coagulation time, as brief as several seconds, which requires that the intensity of light be measured at short intervals, that is, as short as approximately 0.1 seconds. Furthermore, once the reaction solution solidifies, the reaction vessel can no longer be re-used through cleaning. Specifically, the reaction is made at an independent photometric port and the reaction vessel is throwaway. The blood coagulation and fibrinolysis tests include measurement of coagulation factors and measurement of the coagulation-fibrinolysis marker, in addition to measurement of the blood coagulation time. The measurement of coagulation factors is taken mainly at a blood coagulation time measuring section. For the coagulation-fibrinolysis marker, analyses are made with the synthetic substrate method where a chromogenic synthetic substrate is used or the latex coagulating method mentioned earlier. Whereas the conventionally available PT, APTT, and Fbg are substantially fixed for the blood coagulation time the number of coagulation-fibrinolysis marker items are expected to increase to respond to requirements for early diagnosis and treatment for disseminated intravascular coagulation syndromes (DIC), including soluble fibrin monomer complex (SFMC) and plasmin-α2-plasmin inhibitor (PIC), in addition to D dimer and fibrin fibrinogen degradation product (FDP). The need thus exists for improved throughput of the automatic analyzers. In the analyzer disclosed in patent document 2, however, the coagulation-fibrinolysis marker is measured at the photometric port at which transmitted light can be measured. In conventional blood coagulation analyzers, both the coagulation time and the coagulation-fibrinolysis marker are generally analyzed at a fixed photometric port.